Lecterns, pulpits, speakers&#39; stands, and the like



Dec. 24, 1963 N. J. STOWELL 3,115,548

LECTERNS, PULPITS, SPEAKERS STANDS, AND THE LIKE Filed 001. 26, 1960 3 Sheets-Sheet 1 8 a lu k 7 x/ s: 11...... I m a Z s: :1 w m J. M

INVENTOR Wa/fian ji /we BY ATTORNEY Dec. 24, 1963 N. J. STOWELL LECTERNS, PULPITS, SPEAKERS STANDS, AND THE LIKE Filed on. 26, 1960 5- Sheets-Sheec 2 J w////// r/ INVENTOR BY WWW/77 ATTORNEY Dec. 24, 1963 N. J. STOWELL LECTERNS, PULPITS, SPEAKERS STANDS, AND THE LIKE Filed 001;. 26. 1960 3 Sheets-Sheet 5 UWN INVENTOR fl affian jfawe BY WWW Qvm ATTORNEY "Ar o A U United States Patent 3,115,542 LlhC flElllS, rlULPilTS, srnaknns ermine, AND run runs Nathan Jerome tltowell, Misa, assignor to James Willis Hughes, llackson, ll liss. Filed Get, as, 1969, Ser. No. sense 6 Claims. {@l. l79-l) This invention relates to new and useful improvements in lecterns, pulpits, speakers stands, and the like, and the principal object of the invention is to provide a device of this type which, in addition to its usual facilities as a stand and book or note support, also embodies what may be broadly referred to as a public address system including a microphone, an amplifier, one or more speakers, tape recorder and/or record player, et cetera, all selectively usable and contained in an especially constructed easily portable cabinet.

Preferably, the cabinet in accordance with the invention is arranged to accommodate two transversely spaced speakers which may be used stereophonically, and an important feature of the invention resides in providing the cabinet with a removable casing having an open front in communication with a forarninous grille at the front of the cabinet, the casing being partitioned to provide a pair of transversely spaced speaker compartments as well as an amplifier compartment therebetween, with the aforementioned grille serving not only as a passage for sound waves from the speaker compartments, but also for dissipation of heat from the amplifier compartment in a forward direction, so that such heat does not cause discomfort to a speaker standing behind the lectern.

Another important feature of the invention resides in a particular arrangement of the speaker compartments which are provi ed with hollow, box-shaped speaker supports each defining therewithin a sound transmitting chamber which is separate from a static air chamber in the compartment rearwardly of the sound transmitting chamber, the static air chamber being airtight and loaded with static air so as to act upon the energking mechanism of the speaker and restrict effectual frontal passage of undesirable or distortion compliance of the sound emitting mechanism of the speaker, thus controlling compliance or excursion of the sound emitting mechanism to produce only the applied electro-1notive force without undesirable results of phase distortion.

Another important feature of the invention resides in the particular arrangement of the aforementioned sound transmitting chamber of each speaker compartment, such chamber being of a rectangular cross-section and forwardly divergent with a greater divergence in the horizontal than in the vertical plane, so that sound waves zassing forwardly from the chamber are concentrated into an outwardly divergent beam of a rectangular cross-section with a greater horizontal than vertical spread. As such, the sound wave beams, when directed into an auditorium, are spread laterally with substantial effectiveness but are confined in a vertical direction so as to prevent them from bouncing off the auditorium ceiling and causing feedback to the microphone at the lectern.

Some of the advantages of the invention resides in its simplicity of construction, eflicient operation, and in its adaptability to convenient and economical manufacture.

With the foregoing more important objects and features in view and such other objects and features as may be come apparent as this specification proceeds, the invention will be understood from the following description taken in conjunction with the accompanying drawings, wherein like characters of reference are used to designate like parts, and wherein:

FIG. 1 is a front elevational view of a lectcrn in ac- Dec. 24, 1963 cordance with the invention;

FIG. 2 is a side elevational view thereof;

Fit 3 is atop plan View of the same;

PEG. 4 is a rear elcvational View;

FIG. 5 is a vertical sectional view, taken substantially in the plane of the line 55 in FIG. 3

FIG. 6 is an enlarged horizontal sectional view, taken substantially in the plane of the line 6-6 in FIGS. 1 and 7;

FIG. 7 is a vertical sectional view, taken substantially in the plane of the line 7--7 in FIG. 6;

FIG. 8 is a perspective view of the casing used in the invention;

FIG. 9 is an enlarged, fragmentary sectional detail of one of the resilient casing supports;

MG. 10 is an enlarged fragmentary sectional detail of the microphone mount; and

FIG. 11 is a block wiring diagram of the electrical components used in the invention.

Referring now to the accompanying drawings in detail, the lectern in accordance with the invention is designated generally by the reference numeral it) and comprises a cabinet ll made of wood or other suitable material. The cabinet ill includes a front wall ii, a pair of side walls 13, a rear wall l t, a bottom 25 and a top lo, 117. The front wall 12 is provided with a relatively large, rectangular opening in which is mounted a foraminous grille 18 of the type commonly employed for covering loud speakers, and the rear wall is also provided with a relatively large, rectangular opening 19. A horizontal partition 2i is provided in the cabinet flush with the upper edge of the opening 19' in the rear wall 14-, whereby to provide a compartment 2-11 in the upper portion of the cabinet, as shown.

A horizontally elongated, box-shaped casing 22 is re movably positioned in the bottom portion of the cabinet l ll below the partition Ell, the casing 22 being insertable and removable through the opening 19. The casing 22 has an open front which communicates with the foraminous grille and the back panel 23 of the casing is flush with the rear cabinet wall 14 so as to provide a closure for the opening 119 when the casing is inserted in the cabinet.

As is best shown in FIGS. 6 and 8, the casing 22 is provided with vertical partitions 24 which separate the interior of the casing into a pair of transversely spaced speaker compartments 25 and an amplifier compartment 26 therebetween. The compartment 26 accommodates a suitable amplifier unit 27 and when the same is in operation heat is dissipated therefrom through the grille l8 and forwardly from the cabinet, so that it does not cause discomfort to a speaker standing behind the lectern.

Each of the speaker compartments 25 is provided with a hollow, box-shaped speaker support 28 which is disposed in the compartment 25 in a re-entr'ant manner as shown in FIGS. 6 and 7, so as to provide a sound transmitting chamber 29 within the hollow support 255 and a static air chamber 3h in the compartment rearwardly of the chamber 2,. A suitable speaker unit 311 is mounted in each support 2 3 and has its front portion or sound emitting mechanism oriented forwardly into the sound transmitting chamber 2%, while its rear portion or energizing mechanism is disposed in the static air chamber 39. The chamber 34 is air tight and loaded with static air which acts upon the energizing mechanism of the speaker and restricts effectual frontal passage of undesirable or distortion compliances of the sound emitting mechanism of the speaker, thus controlling the compliance or excursion of the sound emitting mechanism to produce only the applied without undesirable results of phase distortion.

Each sound transmitting chamber 29 is of a rectangular cross-section with forwardly divergent sides, the divergence of which in a horizontal plane as indicated at 32 being greater than the divergence in a vertical plane as indicated at 33. Thus, sound waves passing from each speaker 31 through the gri le 18 are concentrated into a forwardly divergent beam of a rectangular cross-section having a greater horizontal spread than vertical spread. Accordingly, when the sound wave beams are directed into an auditorium, for example, they are spread laterally with substantial effectiveness but are confined in a vertical direction so as to prevent them from bouncing off me ceiling and causing feed-back to a microphone 34 at the lectern.

The transverse or lateral spacing of the speaker compartments affords a stercophonic arrangement in a single cabinet. In actual practice the horizontal angle 32 included between the sides of the chambers 29 may be approximately 30 while the included vertical angle is only about 15, and the relatively greater horizontal spread of the sound wave beams causes them to overlap in the auditorium with effective stereophonic results.

The top of the cabinet ll includes the aforementioned top portion 16 which is fixed and the portion 17 which slopes rearwardly and is hinged at its front edge to the portion 16 as indicated at so that it may be swung upwardly for gaining access to the interior of the compartment 2d. The latter compartment may contain other components of the sound reproducing system, as for example, a mixer 36 (FIG. 7), a record player or tape recorder 37 (FIG. 5), etc, these various devices being accessible through openable doors 33, 39 in the top portion 17, so that it is not necessary to open the entire top portion 17 when adjusting any one such device. it is to be noted that the grille extends somewhat above the partition 29 so as to provide an air passage for dissipation of heat from the equipment in the compartment 21.

The entire casing 2?. is preferably provided at the underside thereof with resilient pads or feet 4%} which rest upon the bottom lid of the cabinet and support the casing in a cushioned manner to prevent vibration or jarring of the speakers 31 and amplifier unit 27. The microphone 34 is adjustably supported by a flexible gooseneck 4d mounted in a socket 42 on a suppont plate 43 which, in turn, is secured to the top portion 16 by suitable screws id equipped with shock-absorbing bushings 45, as shown in FIG. 10.

The versatility of my improved lectern for use in auditoriums is best shown by reference [to FIG. 11, in which various component parts of the electrical system are illustrated in block form. The system exemplified in FIG. 11 by way of illustration but not limitation, is designed for stereopihonic results. It is contemplated that the system includes the use of a plurality of microphones 34 which are connected to an amplifier mixer unit 36 by conductors 4-6 and transformers 47. The transformers 47 couple the input signal from the microphones to the input circuit of the mixer unit. For stereophonic bro-adcasting the mixer unit comprises two channels each of which receive signals from separate pick-up microphones. Output signals from channel ll of the mixer are fed via conductor 48 to channel 1 of a power amplifier 59. Output signals from channel 2 of the mixer are fed via conductor 49 to a limiter amplifier 51. The output from the limiter is fed to channel 2 of the power amplifier 50 via conductor 52.

The system contemplates that signals other than from the microphones be fed to the power amplifier 5t Such signals may come from a tape recorder 53, an organ 54, or a phonograph 5d. The signals from the various input sources may be fed into the power amplifier either separately or in any desired combination.

The system also contemplates that the output signals from the power amplifier be fed to various broadcasting devices, such as auditorium loud speakers 31, a radio frequency carrier amplifier 56, and projector input amplifier 57. The radio frequency carrier amplifier 56 is cond nected to a broadcast antenna 58 which will broadcast the voice modulated radio frequency signal to places which are remote from the auditorium in which the lectern is located. Receiving antenna 59 and receiver unit as detect the voice signal and broadcast the audio-frequency sound through loud speaker 61. A broadcast amplifier n2 is provided which has a visual indicator 63 for visually monitoring the broadcast signal. By using two or more loud speakers in an auditorium which are connected to separate channels of the power amplifier a stereophonic cfie .n be produced.

While the wire connections between the component parts of the electrical system which are included in the lectern and attached thereto have not been shown in detail it will be understood that suitable wire connections are provided in accordance with the block diaphragm of FIG. ll. Sockets located in connector panel 64 in the side of the lectern are provided through which the connections to apparatus used as auxiliary to the lectern including the organ, projector amplifier, and radio frequency carrier amplifier may be made. The electrical energy for supplying the amplifiers and loud speakers may also be fed through the connector panel as.

An important feature of my improved lectern is its ability to receive signal inputs from various selected signal sources either simultaneously or separately without excessive distortion because of feedback from the component parts. I have illustrated in FlG. 11 only one system which may be used with my lectern, but other systems, including other signal sources, amplifiers, and output signal receivers may be used within the scope of my invention.

The invention has been described in detail for the purpose of illustration but it will be obvious that numerous modifications and variations may be resorted to without departing from the spirit of the invention as defined in the accompanying claims.

What is claimed as new is:

l. In a lectern, the combination of a cabinet including a front wall provided with a fcraminous grille, a pair of side walls, a top wall, and a back wall provided with an opening, a casing removably positioned in said cabinet through said opening, said casing having an open front in communication with said foraminous grille and including a back panel flush with said back wall and constituting a closure for said opening, partition means provided in said casing and separating the interior thereof into an amplifier compartment and at least one speaker compartment, an amplifier provided in said amplifier compartment, a speaker provided in said speaker compartment, and a microphone mounted on top of said cabinet in circuit with said amplifier and said speaker, said grille affording passage of sound waves from said speaker and dissipation of heat from said amplifier forwardly from the cabinet.

2. The device as defined in claim 1 wherein said speaker compartment includes a sound transmitting chamber of a rectangular cross-section whereby sound waves passin through said grille outwardly from said cabinet are concentrated into a beam' of a rectangular cross-sectional form.

3. The device as defined in claim 1 wherein said speaker compartment includes a sound transmitting chamber of a rectangular cross-section with forwardly divergent sides whereby sound waves passing through said grille outwardly from said cabinet are concentrated into an outwardly divergent beam of a rectangular crosssectional form.

4-. The device as defined in claim 1 wherein said speaker compartment includes a sound transmitting chamber of a rectangular cross-section with forwardly divergent sides, the divergence of the sides of said chamber being greater in a horizontal plane than in a vertical plane whereby sound waves passing through said grille outwardly from said cabinet are concentrated into an out- 6. The device as defined in claim 1 further provided with vibnartion dampening means separating said casing from direct physical contact with said cabinet.

References Cited in the file of this patent UNITED STATES PATENTS 2,063,224 Bowles Dec. 8, 1936 2,224,919 Olson Dec. 17, 1940 2,830,118 Kohler Apr. 8, 1958 2,840,178 Boleslav June 24, 1958 2,921,135 Hoodwin Jan. 12, 1960 

1. IN A LECTERN, THE COMBINATION OF A CABINET INCLUDING A FRONT WALL PROVIDED WITH A FORAMINOUS GRILLE, A PAIR OF SIDE WALLS, A TOP WALL, AND A BACK WALL PROVIDED WITH AN OPENING, A CASING REMOVABLY POSITIONED IN SAID CABINET THROUGH SAID OPENING, SAID CASING HAVING AN OPEN FRONT IN COMMUNICATION WITH SAID FORAMINOUS GRILLE AND INCLUDING A BACK PANEL FLUSH WITH SAID BACK WALL AND CONSTITUTING A CLOSURE FOR SAID OPENING, PARTITION MEANS PROVIDED IN SAID CASING AND SEPARATING THE INTERIOR THEREOF INTO AN AMPLIFIER COMPARTMENT AND AT LEAST ONE SPEAKER COMPARTMENT, AN AMPLIFIER PROVIDED IN SAID AMPLIFIER COMPARTMENT, A SPEAKER PROVIDED IN SAID SPEAKER COMPARTMENT, AND A MICROPHONE MOUNTED ON TOP OF SAID CABINET IN CIRCUIT WITH SAID AMPLIFIER AND SAID SPEAKER, SAID GRILLE AFFORDING PASSAGE OF SOUND WAVES FROM SAID SPEAKER AND DISSIPATION OF HEAT FROM SAID AMPLIFIER FORWARDLY FROM THE CABINET. 